The Hubble Space Telescope is famous for finding black holes. It can pick out thousands of galaxies in a patch of sky the size of a thumbprint. The most powerful space telescope ever built, the Hubble provided evidence that the Universe is slowing down in its infinite rush into whatever lies beyond.
But the Hubble’s cosmic firepower was recently put to a new purpose: searching for a billowing cloud of water vapor on Jupiter’s moon Europa. The plumes are a sign that extraterrestrial life could be lurking within our own Solar System. Before we head way out there, we need to know a little about the eruptions happening at home.